A conventional thermoelectric generator of this type has been known that includes an inner tube, an outer tube, and thermoelectric conversion modules. The inner tube has at least one heat collecting surface on which heat collecting fins are formed on its inner surface. The inner tube receives exhaust gas discharged from an internal combustion engine. The outer tube has a heat radiating surface opposed to the heat collecting surface of the inner tube and is formed of a cooling jacket in which coolant (cooling medium) circulates. The thermoelectric conversion modules are located between the heat collecting surface of the inner tube and the heat radiating surface of the outer tube. The thermoelectric generator has a high-temperature end face (high-temperature part) in close contact with the heat collecting surface. The thermoelectric conversion modules are stored in a space portion surrounded by the outer tube (refer to Patent Document 1, for example).
In the thermoelectric generator, the inner tube and the heat collecting fins are formed of stainless steel plates to prevent corrosion due to exhaust gas.